1. Field of the Invention
The invention relates to a motive power unit, in particular for automobile vehicles, and is more particularly concerned with a motive power unit of this kind equipped with a hydrostatic transmission device.
2. Description of the Related Art
A conventional hydrostatic transmission device usually comprises at least one pump feeding a liquid, usually oil, into a volumetric hydraulic motor. The piston of the pump can be operated by a heat engine, usually an internal combustion engine. EP disclosure 0 044 252 discloses such an arrangement. In a system of this kind regulation means are provided for adapting the flowrate of one of the two subsystems if that of the other varies. This is achieved by changing its volumetric capacity, usually by varying the active stroke.